Infusion pump devices and systems are relatively well known in the medical arts, for use in delivering or dispensing an agent, such as insulin or another prescribed medication, to a patient. A typical infusion pump includes a pump drive system which typically includes a small motor and drive train components that convert rotational motor motion to a translational displacement of a plunger (or stopper) in a reservoir that delivers medication from the reservoir to the body of a user via a fluid path created between the reservoir and the body of a user.
In practice, it is desirable to conserve power consumption by portable or battery-powered electronic devices, such as portable fluid infusion devices, to prolong battery life. Brushless direct current (BLDC) electric motors may be appealing for some applications because of their relatively high efficiency and relatively compact size. However, the BLDC is potentially susceptible to magnetic interference by virtue of the permanent magnets on its rotor. For example, a relatively large magnetic field could potentially displace the rotor in an uncontrolled manner independently of the motor controller. Accordingly, it is desirable to protect against such uncontrolled displacement of the rotor without compromising efficiency.